000 WTNT41 KNHC 041452 TCDAT1 HURRICANE JOAQUIN DISCUSSION NUMBER 28 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015 1100 AM AST SUN OCT 04 2015 The overall cloud pattern of Joaquin has changed little since the previous advisory. An Air Force Reserve Unit reconnaissance aircraft has reported peak 700-mb flight-level winds of 107 kt and SFMR surface wind values of 90 kt during its mission so far this morning, so the initial intensity has been decreased to 95 kt for this advisory. A ragged eye feature is just becoming apparent on the Bermuda radar, with strong inner-core rain bands currently located less than 50 nmi southwest of the island. Recon center fixes indicate that Joaquin has made the expected turn toward the north-northeast, and is now moving 030/15 kt. Joaquin is forecast to move around the western portion of a modest mid-level ridge to its east and ahead of an eastward-moving deep-layer low located over the southeastern United States. This is expected to result in the hurricane moving toward the north-northeast today and tonight, followed by a turn toward the northeast on Monday. On the short term forecast track, the center of Joaquin is expected to pass about 60 nmi west and northwest of Bermuda during the next 12-24 hours. By days 2-5, Joaquin is forecast to accelerate to the east-northeast as the cyclone gets caught up in the fast mid-latitude westerlies. The new NHC track forecast is essentially just an update of the previous advisory track, albeit slightly slower, and lies down the middle of the tightly packed track model guidance. Excluding a slight respite this afternoon, the vertical wind shear is forecast to increase during the next two days, with the mid-level environment expected to dry out with humidity values decreasing to around 50 percent. These less favorable conditions should result in gradual weakening for the next 48 hours or so, followed by more significant weakening on days 3-5 when Joaquin is expected to become an extratropical cyclone over the north Atlantic where SSTs are 20C-24C and vertical shear is forecast to be 45-50 kt. Extratropical transition is forecast to occur by 96 hours, but it is possible that it could sooner by around 72 hours as per guidance from the SHIPS and LGEM statistical-dynamical models, and the EMCWF model. The intensity forecast is similar to the previous advisory and the consensus model IVCN through 72 hours, and is based on guidance from the Ocean Prediction Center at 96 h and 120 h when the cyclone is expected to be an extratropical low. FORECAST POSITIONS AND MAX WINDS INIT 04/1500Z 31.0N 66.8W 95 KT 110 MPH 12H 05/0000Z 32.8N 65.9W 85 KT 100 MPH 24H 05/1200Z 34.8N 64.8W 80 KT 90 MPH 36H 06/0000Z 36.6N 62.7W 80 KT 90 MPH 48H 06/1200Z 38.4N 58.5W 75 KT 85 MPH 72H 07/1200Z 42.3N 45.5W 60 KT 70 MPH 96H 08/1200Z 46.4N 29.9W 55 KT 65 MPH...POST-TROP/EXTRATROP 120H 09/1200Z 51.4N 19.7W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Stewart